The present invention relates to a novel Lactobacillus strain, which possesses valuable pharmaceutical characteristics. The invention also relates to pharmaceutical compositions and products for personal care comprising the strain, as well as use of the strain for prevention of urogenital infections.
(All citations in the following description are incorporated by reference).
The usual bacterial flora in the urogenital region in constituted by a complex eco-system comprising more than 50 different bacterial species (Hill et al., Scand. J. Urol. Nephrol. 1984;96 (suppl.):23-29). The normal flora is dominated by bacteria belonging to the genus Lactobacillus (LB) which are Gram positive rods adapted to the environment in the vagina of the fertile woman. These bacteria also contribute to the maintenance of the specific milieu and the ecological balance in the vagina.
Beside the complex interaction pattern of the multitudinous bacterial flora of the vagina and the rest of the urogenital region, it is necessary to consider the variation of physical conditions that can influence bacterial growth and adhesion properties. Some LVS strains inhibit growth of potentially pathogenic bacteria by various mechanisms. The metabolism of LB results in formation of organic acids, above all lactic acid and acetic acid, which contribute to the low pH of vaginal fluid which is unfavourable for many other species. LB may also produce soluble substances which directly inhibit growth of potentially pathogenic bacteria and yeast. They can also produce hydrogen peroxide which is toxic to bacteria lacking the enzyme catalase, such as gram-negative anaerobic rods and Enterobacteriacae. These inhibiting characteristics may vary considerably between different LB strains (Hooton et al., JAMA 1990; 265:64-69).
Weakness of the natural deference system may allow potentially pathogenic micro-organisms to cause clinical infection, for example in connection with medication, inferior personal care, or shifts in the microflora of skin or mucous membranes. The normal flora of the vagina is dominated by LB and the surrounding pH is lower than 4.5. Yeast and enterobacteria are scanty or absent (Redondo-Lopez et al., Rev. Inf. Dis. 1987; 12:856-872). Shifts of the vaginal bacterial flora can be found in connection with different pathogenic conditions. There is an increased amount of enterobacteria in the vagina and urethral orifice of women suffering from recrudescent urinary tract infections and they also have a urogenital flora depleted of lactobacilli (Marrie et al. J. Clin. Microbiol. 1976, 8, 67-72). It is also known that the frequency of infections increase in connection with antibiotic treatment of other infections (Stamey, Rev. Inf. Dis. 1987: 9(suppl. 2):195-208; Reid et al., Curr. Opin. Inf. Dis. 1991; 4:37-41). In addition, it has been demonstrated that children who have a history of frequent episodes of antibiotic treatment are more prone to contract urinary tract infections (Mxc3xa5rild et al., Ped. Inf. Dis. 1990; 22:43-47).
In bacterial vaginosis the amount of LB is decreased and pH is increased. There is also a dominance of Bacterioides species, Gardnerella vaginalis and Mobiluncus (Redondo-Lopez, supra). Vaginitis, associated with an increased amount of entero-bacteria, is often a tangible problem in connection with antibitotic treatment. Common oral administration of penicillin results in the accumulation of the substance in vaginal fluid (Sjxc3x6berg et al., Obstet. Gynecol. 1990; 75:18-21) followed by colonisation by enterobacteria and yeast (Sjxc3x6berg et al., Gynecol. Obstet. Invest. 1992; 33:42-46). Investigations in monkeys (Macaca fascicularis) have revealed that vaginal administration of amoxicillin impairs the ability of the normal bacterial flora to inhibit colonisation of urinary tract-pathogenic E. coli (Herthelius et al., Infection 1988; 16:263-266).
During pregnancy the composition of the vaginal flora may influence the morbidity of the fetus and child. Occurence of group B streptococci (GBS) in the faecal and vaginal flora is common (up to 30% of all pregnant women). These bacteria do not normally constitute a threat to the woman""s health. However, GBS may cause serious infections in the new-born child. In these cases, bacteria are transmitted vertically from mother to child before or in connection with birth. Other bacteria can also be transmitted in this way and cause infections in the child. There is also a strong connection between bacterial vaginosis and premature birth (Martius et al., Arch. Gynecol. Obstet. 1990; 247:1-13). The mechanisms behind this phenomenon are not known. It has been shown that a shift of the vaginal flora towards dominance of Gram negative species increases the amount of the enzyme phospholipase A2, which in turn may initiate prostaglandin synthesis starting from arachidonic acid (Bejar et al., Obstet. Gynecol. 1981; 57:479-482). The vaginosis flora also produces large amounts of endotoxin (Sjxc3x6berg et al., Obstet. Gynecol. 1991; 77:265-266), which may induce endogenous prostaglandin synthesis (Romero et al., Obstet. Gynecol. 1989; 73:31-34), possibly mediated by interleukines.
The theoretically positive characteristics of LB have motivated their use in commercial preparations with the intend use to supplement and strengthen the vaginal flora. Success has been variable and often the available preparations contain considerably lower numbers of LB than what has been stated. Some preparations have also been contaminated (Hughes et al., Obstet. Gynecol., 1990; 75(2):244-248). In order to supplement and improve the normal bacterial flora in the urogenital region by addition of LB, it is necessary to carefully select the bacterial strains to be used. A LB strain that is suitable for this purpose should fulfil the following criteria.
1. The LB strain should produce high amounts of soluble substances with growth inhibiting capacity on enterobacteria, group B streptococci, staphylococci and yeast.
2. The LB strain should be able to be transferred to skin and mucosal surfaces of the urogenital region.
3. The LB strain should be able to adhere to epithelial surfaces in the urogenital region.
4. The LB strain should be able to endure storage for a long period of time, and it must be possible to induce the strain in different kinds of preparations.
5. The LB strain should be able to retain its viability and characteristics in an article or preparation upon use.
6. The LB strain should not be sensitive to spermicidal preparations containing nonoxynol-9.
7. The LB strain should be isolated from the urogenital tract of human female.
8. The LB strain should permit existence of the human urogenital LB flora.
Therefore, there is a demand for strains, fulfilling these requirements.
A novel strain of Lactobacillus plantarum, referred to as LB931, has been isolated, which fulfils requirements listed above. The strain has been deposited on Jan. 27, 1998 at Dsmz-Deutsche Sammlung von Mikroorganisem und Zeelkultren, Mascheroder Weg 1b D-38124 Braunschweig. It has been assigned accession number DSM11918. Accordingly LB931 may be used for treating and/or preventing urogenital infections. LB931 can advantageously be included in pharmaceutical compositions and in products for personal care, such as diapers and sanitary napkins.
As disclosed herein, the term xe2x80x9cLBxe2x80x9d refers to bacteria of the genus Lactobacillus.
As disclosed herein, the term xe2x80x9cUrogenital regionxe2x80x9d refers to perineum, urethra and vagina.
As disclosed herein the term xe2x80x9cabsorbent articlexe2x80x9d relates to products suitable for absorbing a body fluid, such as blood or urine. Examples of such articles are feminine hygiene products, incontinence guards, and diapers.
As disclosed herein, the term xe2x80x9cGBSxe2x80x9d refers to group B Streptococcus.
As disclosed herein, the term xe2x80x9clactic acid bacteriaxe2x80x9d relates to bacteria producing lactic acid, such as bacteria belonging to the genera Lactobacillus and Lactococcus.
By the term xe2x80x9ccfuxe2x80x9d is meant colony-forming units.
The present invention relates to a novel strain of Lactobacillus plantarum, referred to as LB931 (DSM11918). This bacterial strain is valuable for preventing and/or treating urogenital infections as it inhibits growth of a large number of pathogenic micro-organisms. The strain is endurable and readily survives long periods of storage in room temperature. Accordingly products containing LB931 have a long shelf life. The strain can easily be transferred to the human skin and vaginal epithelium. LB931 is resistant to therapeutic concentrations of some antibiotic substances and spermacidal compounds.
The inhibition characteristics of LB931 has been investigated. Examples of bacteria species which are successfully inhibited are Escherichia, Klebsiella, Proteus, Staphylococcus and group B Streptococcus. LB931 is therefore useful for preventing and/or treating infections caused by these micro-organisms.
As noted above, the present invention also provides a variety of pharmaceutical compositions, preferably suitable for topical administration, comprising LB931 along with pharmaceutically or phsyiologically acceptable carriers, excipients and/or diluents. Generally, such carriers should be non-toxic to recipients at the dosages and concentrations employed. Normally, the preparation of such compositions entails the combination of the therapeutic agent with buffers, thickening agents of gel-forming agents such as glycerine, polyethylene glycol, etc. Antioxidants such as ascorbic acid, low molecular weight (less than about 10 residues) polypeptides, proteins, carbohydrates including glucose, sucrose and dextrins, and other stabilisers and excipients may be included. Possible pharmaceutical compositions are ointments, creams, liquid solutions, suppositories or capsules.
The present invention also relates to absorbent articles comprising LB931. Such an article may include a permeable outer sheet which is intended to be in close contact with the skin of the wearer, a preferably liquid-impermeable backing sheet which is intended to lie distal from the wearer in use, and an absorbent structure arranged between the outer sheet and the backing sheet. In some cases, an additional sheet in the form of e.g. wadding or like material, may be placed between the outer sheet and the absorbent structure. The micro-organisms exhibiting antagonistic properties may be arranged in different parts of the absorbent article, for instance in the outer sheet, in the absorbent structure of the absorbent article, between two of the layers of the absorbent article, in a loose insertproduct in the absorbent article, or in some other way.